This invention relates to gas turbine combustors and particularly to a liquid fuel cartridge designed to prevent formation of internal coke deposits about the fuel nozzle tip.
The formation of coke deposits at the tip of a fuel injector nozzle can interfere with the desired fuel/air mixture delivered to the combustion chamber throughout the various stages of combustion, and thus negatively impact on the reduction of oxides of nitrogen (NOx) required by exhaust emissions regulations.
One attempt to solve the coke formation problem is described in U.S. Pat. No. 6,715,292. A coke-resistant fuel injector for a low-emission combustor is formed with a pressure-atomizing core nozzle and an airblast secondary injector. The airblast portion includes inner and outer air passages for injecting co-annular, co-swirling streams into the combustor can. An air distribution baffle extends radially across the inner air passage to divide the inner airstream into a substream and a plurality of air jets. The presence of the air baffle and co-swirling inner and outer air streams is said to promote superior fuel-air mixing which promotes clean burning and resists coke formation.